Manufacture of carbamates of tertiary alcohols.



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HEINRICH THBON, OE FRANKFORT-ON-THE-MAIN, EDUAIRD SPRNGER-TS, OF BIELBRICH, AND ZCARL FREUND, 0F FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNORS TO VEREINIGTE CHININFABRIKEN ZIMMER & 00., G. M. B. 1-1., OF FBANKFORT-ON-THE- MAIN, GERMANY, A FIR-MOI GERMANY.

IVIANUFACTURE OF CARBAMATES OF TERTIARY ALCOHOLS.

Specification of Letters Patent.

No Drawing.

Patented Feb. 13, 1912.

Application filed July 10, 1911. Serial No. 637,781.

To oZZ whom 2'25 may concern:

Be it known that we, Hmxnron Timon, residing at Frankfort-on-the-ll/lain, EDUARD Srnorzonn'rs, residing at Biebrich-on-the- Rhine, and CARL FRICUND, residing at Franktort-on-the-Main, Germany, subjects ot the German lhnperor, have invented certain new and useful Improvements in the. ll'lanutacture of Carbamates of Tertiary Alcohols, of which the following is specification.

T he manufacture. of esters of tertiary alcohols, when compared with that of the esters of primary and secondary alcohols, presents various difficulties which till now have made it impossible to prepare the carbamates of the tertiary alcohols, 2'. 6., of their urethanes. We have now succeed d in obtaining these carbamatcs (urethanes) by causing urea chlorid. to react on tertiary al cohols in the presence 01 bodies binding hydrochloric acid. For this purpose the tertiary alcohols may be converted into. their metallic compounds, the metal binding the hydrochloric acid in the further course of the reaction; or the bodies which bind the hydrochlor" acid, namely organic, or inorganic, basic substances, may be added directly to the reaction mixture.

The following are examples of how this invention may be performed, but we do not limit ourselves to these. The parts are by i weight.

if rampic I. ll[m2.ufcwture 0 f the C(H'l/(Ufifli of tertiary (mtg Z alcohol. 88 parts of tertiary amyl alcohol (amylen-hydrate) mixed with 600 parts of benzene are boiled with 23 parts of sodium, until almost the whole is dissolved. The liquor is decanted, well cooled and slowly mixed, while being stirred, with 79.5 parts of urea chlorid which has been diluted with 400 parts of benzene. rafter allowing the mixture to stand for some time, the liquoris drawn oil", by suction, from the sodium chlorid and the henzene is distilled oil. In mining the oily resi due with benzene, crystallization takes place. The liquor is drawn oil by suction and the crystals washed with benzene and recrystallized from dilute alcohol.

The carbamate of tertiary amyl alcohol (NH CO.,.C ,H consists of fine colorless needles having a feeble odor and taste of camphor and melting at from 83 to 86 I centigrade. It is readily soluble in most ort ganic solvents, but ditlicultly'soluble in pci troleum benzene and water. It has, as against the amy-l ester of allophanic acic, y which is also a solid, odorless body, the advantage of having a much superior hypnotic action. sl'hethcr this is a consequence of the easier decomposibility, or a peculiarity of the urethanes, isuncertain. Emmnplc If. lllaimfactm'c 0f the carbm mate of tertiary (mtg Z alcoizoL -To the Grignards reaction products obtained, .in the usual manncntrom 24.3 parts of magnesium, 20!) parts of other and 64.5 parts of ethyl chlorid, 3-8 parts of tertiary amyl alcohol are slowly added. When the evolution of ethane is over, 79.5 parts of carbamic acid chlorid which'havc been diluted with 200 parts of benzene are slowly added while, stirring and well cooling. After standing for some time, the mixture is poured into ice, the ethereal solution is separated from the water, washed with water in which sodium carbonate is dissolved and dried by means of calcium chlorid. The other and benzene are then distilled oil and the residue is recrystallized from benzene.

Exam/7J0 11]. 1l[ (m'ufaclm'e 0 alt-ethylmct/zg Z carl nol carha-nmtc.'lhe Grignard compound manufactured, in the usual way, from 24.3 parts of magnesium, 250 parts of anhydrous ether and 64:15 p: rts of ethylcl'llorid. To this are added 72 parts one molecular proportion) or ethyl-methyllretone and, when the reaction is ompleted, 79.5 parts of urea chlorid (one molecular proportion) are run into the mixture while cooling. The magnesium is extracted from the reaction product by means or dilute hydrochloric acid, the ethereal solution is dried by means of calcium chlorid, the ether expelled and the residue distilled in oacuo. In this way the carbamate of di} ethylmethyl-carbinol is obtained in colorless needles having an odor like that of camphor.

Example 1V. illtmufactwc the carbomate of tertiary (miyZ-aZo0/i0Z.-8S parts 01'' tertiary ainyl alcohol are mixed with 121 parts of di-methyl-anilin and 300 parts of benzene. To this mixture is then added, slowly and while cooling, 'a solution of 79.5 parts of urea chloridiin 200 parts of benzene. After being, allowed to stand for several hours. the mixture is shaken with diluted hydrochloric acid, and the benzene solution is then dried by means of calcium chlorid and concentrated. On cooling the amyl ester of carbamic acid crystallizes out.

Ewample V. Manufacture of oarbamate of tertiary amyl aZc0h0Z.-88 arts of "tertiary amyl alcohol are mixed with 53 parts of anhydrous sodium carbonate and 300 parts of benzene. This mixture is, While stirred and cooled, mixed with a solution of 79.5 parts of urea chlorid in 200 parts of benzene. The reaction product is Washed With Water, the benzene solution dried by means of calcium chlorid, and the greater part of the benzene distilled off on the Water bath. On cooling the amyl ester of carbamic acid crystallizes out.

We claim:

-1. The herein described process of the productiou'of carbamac acid esters of tertiary alcohols Which consists in causing ureachlorid to react on tertiary alcohols in the presence of a substance which is able to bind hydrochloric acid.

2. Carbamic'acid esters of tertiary alcohols obtained by causing ureachlorid to re act on a tertiary alcohol in the presence ofa substance able to bind hydrochloric acid.

3. Carbamic acid ester of tertiary amyl alcohol obtained by causing ureachlorid to react on tertiary amyl alcohol in the presence-of a substance able to bind hydrochloric acid.

In testimony whereof We have signed our names to this specification in the presence of tWo subscribing Witnesses. v

HEINRICH rrrnonr EDUARD SPRONGERTS. CARL FREUND.

Witnesses:

JEAN GRUND, CARL GR ND. 

